In this review, we will be comparing Concord and HDI-3600, two Passive Floor-standing speakers from KLH and JBL.
Let's have a brief look at the main features
of KLH Concord and JBL HDI-3600 first before getting into our more
detailed comparison.
| Key Specs | KLH Concord | JBL HDI-3600 |
|---|
| Brand | KLH
United States · founded 1957 | JBL
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" | 1" |
|---|
| Woofer | 2 x 6.5" Kevlar | 3 x 6.5" Aluminum |
|---|
| Frequency response | 28-23k Hz | 38-30k Hz |
|---|
| Sensitivity | 94 dB | 90 dB |
|---|
| Impedance | 8 ohms | 4 ohms |
|---|
| Power range | up to 225 watts | 20-250 watts |
|---|
| Weight | 20.45kg / 45lbs | 28.09kg / 61.8lbs |
|---|
| Dimensions (H x W x D) | 40-3/8" x 8-5/16" x 14-15/16"
1026.0 x 212.0 x 380.0mm | 40-7/16" x 10-3/16" x 13-9/16"
1028.0 x 259.0 x 345.0mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Concord and HDI-3600 are 2-way speakers.
KLH ConcordJBL HDI-3600
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
KLH Concord |
JBL HDI-3600 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 6.5-inch
|
3 x 6.5-inch
|
Concord features a 1" anodized aluminum Tweeter and 2 x 6.5" Kevlar Woofer. On the other hand, the HDI-3600 features a 1" Tweeter and 3 x 6.5" Aluminum Woofer.
Frequency Response
Concord has a frequency range of 28-23k Hz whereas HDI-3600 has a frequency range of 38-30k Hz. With a minimum frequency of 28Hz, the Concord can go significantly deeper on the low side and provide stronger bass compared to the HDI-3600's min frequency of 38Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
Concord is a 8 ohms speaker compared to the HDI-3600 which has a nominal impedance of 4 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the HDI-3600 can provide this impedance level.
These two speakers also have different sensitivity levels. Concord sensitivity is rated at 94 dB and the HDI-3600's is rated at 90 dB. This 4 dB difference makes the KLH Concord a more sensitive speaker compared to JBL HDI-3600, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
HDI-3600 can handle a max power of 250 watts RMS, whereas Concord has a max power handling value of 225 watts RMS, 25 watts less than the HDI-3600.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
Input Type and Bi-Amping / Bi-Wiring
HDI-3600 features 5-way post posts which make bi-amping or bi-wiring possible. Concord has a 5-Way post which doesn't feature bi-amping/bi-wiring.
KLH Concord's 5-Way post terminals
Physical Specs
The size of a speaker can sometimes be an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare KLH Concord's and JBL HDI-3600's external dimensions. KLH Concord has external dimensions of 1026.0 x 212.0 x 380.0mm (40-3/8 x 8-5/16 x 14-15/16inch) whereas JBL HDI-3600 has external dimensions of 1028.0 x 259.0 x 345.0mm (40-7/16 x 10-3/16 x 13-9/16inch).
KLH Concord is 47mm narrower and 2mm shorter than JBL HDI-3600 but it is also 35mm deeper.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the KLH Concord is approximately 805.6cm2 / 124.9inch2 and base area of the JBL HDI-3600 is approximately 893.6cm2 / 138.5inch2. The Concord requires 10% less surface area than the HDI-3600 which gives it a small advantage on placement in tight spaces.
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The KLH Concord weighs 20.45kg / 45lbs and the JBL HDI-3600 weighs 28.09kg / 61.8lbs. This makes the HDI-3600 37% heavier than the Concord.
Here is a comparison of how Concord and HDI-3600's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
What's in the Box of KLH Concord?
Here are the items that are included inside the box of Concord:
- Floorstanding loudspeaker
- Grille
- 4 Spike feet (w/ locking nut attached)
- 4 Protective discs
- 4 Rubber feet
- Port plug
- Manual
- ATTENTION! note
What's in the Box of JBL HDI-3600?
Here are the items that come with the HDI-3600:
- Floorstanding loudspeaker
- Grille
- 2 Jumper-straps (pre-installed)
- 4 Spike feet
- Owners Manual
 Sensitivity |
94 dB
vs
90 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Low Frequency Response |
28 Hz
vs
38 Hz
|
Generates deeper bass |
 Height |
1026mm
vs
1028mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
805cm2
vs
893cm2
|
Takes less floor space |
 Price per pair* |
1000USD
vs
4180USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
250 watts
vs
225 watts
|
Handle more power from your amplifier |
|
Number of Woofers |
3
vs
2
|
More woofers |
 High Frequency Response |
30k Hz
vs
23k Hz
|
Generates higher frequency |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
| General |
KLH Concord |
JBL HDI-3600 |
| Brand |
KLH |
JBL |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 225 watts |
20-250 watts |
| Sensitivity |
94 dB |
90 dB |
| Impedance |
8 ohms |
4 ohms |
| Frequency Response |
28-23k Hz |
38-30k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
3 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Kevlar |
Aluminum |
| Woofer Surround Material |
Butyl Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
1026.0mm (40.4") |
1028.0mm (40.5") |
| Width |
212.0mm (8.3") |
259.0mm (10.2") |
| Depth |
380.0mm (15") |
345.0mm (13.6") |
| Weight |
20.45kg (45lbs) |
28.09kg (61.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
MDF/Wood-veneer |
| Available Colors |
Black |
Grey |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
Yes |
Other |
|
|
| Parts Warranty |
10 Years |
5 Years |
| Labor Warranty |
10 Years |
5 Years |
These sit in different price classes - JBL HDI-3600 costs roughly 4.2x what KLH Concord does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | A | KLH Concord digs deeper - 28Hz against 38Hz. |
| Amplifier needs | A | KLH Concord is more sensitive (94dB vs 90dB), so it goes louder on the same amplifier. |
| Amplifier match | A | KLH Concord is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | evenly matched | Similar power handling (225W vs 250W). |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | B | JBL HDI-3600: bi-amping. |
| Price | A | KLH Concord is cheaper - $1,000 against $4,180, about 76% less; arguably a different class. |
A KLH Concord B JBL HDI-3600
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
KLH Concord is the easier recommendation: it leads on most of the measured areas and costs less. Take JBL HDI-3600 if its size, looks or fit in your room suit you better. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 38Hz anyway, so judge these on the other rows instead. If your amplifier is modest, vintage or valve-based, KLH Concord is the safer partner - the other will want more current or more watts to sound its best.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.